The present invention relates to a piece of ammunition having a dentonator in a plastic housing containing a hollow charge for use in the disposal/destruction of explosive objects.
The declared aim of numerous countries and humanitarian organizations is to clear the countless minefields scattered over the globe and to dispose of the unexploded bombs still to be found in all former theatres of war.
The earlier practice of detonating mines and unexploded bombs by means of other weapons has proved to be highly dangerous and often also ineffective. Continuing development and the use of proximity fuses, vibration fuses and fuses responding to magnetic-field changes makes the clearing of mines immensely more difficult and increases the cost immeasurably.
Devices of the present general type (DE-C1-36 23 240) and employ a xe2x80x9clow orderxe2x80x9d technique, i.e. the piercing power of a blastxe2x80x94forming hollow charge mounted e.g. on a tripod is adapted to the casing of the piece of ammunition to be disarmed so that the hollow charge pierces the latter in a controlled manner without initiating it. In this way, the piece of ammunition can be disposed of relatively safely by removal of the explosive charge or by combustion thereof.
However, the necessary adaptation of the piercing power is problematic because this can only be done empirically, either by means of different charges or, as known from DE-C1-36 23 240, by the selective attachment of metal (in practice brass) components reducing the blasting power. Although the known device has a relatively low metal content, a further metal is introduced into the system by way of the attached component in addition to the metal lining, which can cause the piece of ammunition to detonate when modern detonators are brought close and, at least in the case of relatively large minefields, causes lasting damage to the soil by burdening it with heavy metals. In addition, the expense of clearing, often in locations which are accessible only with difficulty, is great owing to the necessary adaptation of the blasting power to the object to be cleared and requires additional logistics.
GB-A-2 254 402 discloses a cutting charge encapsulated in a plastic housing so as to be water-tight and designed principally for marine-technology applications. The lining used is the preferred lining and comprises a ductile, high-density material such as copper. However, the also mentioned possibility of using plastic, ceramic or glass is at the same time rejected because these have the tendency to pulverize on detonation. Owing to its linear cutting blast, a cutting charge is fundamentally unsuitable for the disposal of weapons: its piercing power is too low.
A break-up charge (AT-B-398 634) with a tripod for simplified vertical positioning of the charge has insertion openings in which rod-type feet of various lengths are held by friction. The disadvantage is that the angular position of the break-up charge is not adjustable, with the result that the effectiveness of the charge is at the very least impaired, depending on the ground and the size of the piece of ammunition to be destroyed.
An improved tripod is described in U.S. Pat. No. 5,210,368. The height of this tripod can be adjusted so that the detonator of the piece of ammunition to be destroyed can be triggered by remote control. The relatively low height above the ground and the limited rotatability relative to the respective horizontal plane prevents its use in accordance with the low order technique.
U.S. Pat. No. 5,301,594 discloses a stationary machine for disarming unexploded bombs, for sampling and sealing. This machine is entirely unsuitable for field use, in particular for clearing mines.
A device according to DE-A1-195 14 122 is suitable for detonating a plurality of objects with simultaneous or sequential, central detonation. This device requires blasting charges to be fixed to the weapon to be destroyed, which in a good many cases is too dangerous and in particular unsuitable for clearing minefields, etc.
With weapons disposal systems or EOD (explosive ordnance disposal systems), there is always the danger of premature triggering during installation in the area of the mines, e.g. caused by the reaction of electromagnetic sensors contained in mines, by the metal parts in the EOD and/or by resulting field changes, in particular by movement of explosive charges with inserted metal linings.
These linings, in particular when they comprise heavy metals, additionally cause further emissions, especially in areas with a high density of mines, and harm the fauna, flora, soil, ground water and surface water quite considerably and permanently.
Surprisingly, a projectile-forming hollow charge with such an amorphous, non-electrically conductive lining can safely detonate mines and unexploded bombs up to a distance of several meters or at least make them safe.
The subject of the invention is advantageously aimed at the target (weapon) by the means attached to a cover and/or the housing, although the actual alignment is carried out by known mechanical and/or optical devices.
It has been shown that low levels of energy are adequate for weapons disposal, namely because in most cases it is sufficient to pierce the housing and/or the detonating chain of the dangerous piece of ammunition by means of a hollow charge rather than having to detonate or at least deflagrate it, as previously thought.
On the basis of this knowledge, relatively large weapons can also be disposed of with little technical and financial expenditure, i.e. can be made safe to the extent that they can be safely destroyed, for example by subsequent controlled combustion.
On the basis of current knowledge, technical glass and also organic glass, ceramics, in particular aluminium oxide, and numerous plastics with relatively high density, such as polytetrafluoroethylene and polypropylene, are suitable as materials for the linings. The concept of a non-electrically conductive, amorphous material, i.e. an electrical non-conductor, also includes glass mixtures to which metals or metal oxides have been added to an extent that the glasses remain non-conductive and consequently are not detected by conventional metal detectors used for mines and do not trigger the latter.
It has been shown that the effectiveness of amorphous linings is increased by their formation as a projectile-forming charge.
A cup-shaped formation of the lining produces a shaping process during the first 15 cm of its flight, corresponding to an almost ideal shape of a projectile and achieving an extensive piercing effect in the target.
For technical and economical reasons, a lining of glass is preferred.
Linings of ceramic, in particular A12O3, have also been tested, but these are uneconomical to manufacture owing to the necessary sintering process and the required finishing process (grinding). The arrangement of a ball-and-socket joint enables the hollow charge to be aimed at the target in the simplest manner.
A support which further increases the versatility of the EOD has proved successful. By means of selectively insertable supporting rods, the height of the EOD can be fixed within broad limits. Predetermined breaking points permit simple adjustment of the supporting rods to the desired height and additionally bring about the desired xe2x80x9cdisintegrationxe2x80x9d of the rods on detonation.
The incorporation of supporting ribs inside the housing allows the EOD to be placed directly on the weapon to be destroyed and additionally provides mechanically satisfactory centering of the lining.
The EOD can be assembled particularly easily by means of the structural arrangement comprising an annular groove. A tapered annular groove produces a clamping effect which further simplifies assembly.
The insertion of a detonator into a hollow cylinder is particularly advantageous.